Looks like there's some fairly cheap "diy water test kit" on Amazon. I'd expect them to work reasonably well, at least for lead. The chemistry is pretty simple

Looks like there's some fairly cheap "diy water test kit" on Amazon. I'd expect them to work reasonably well, at least for lead. The chemistry is pretty simple. Whether they can detect low concentrations is another matter. You could boil a pot of water until most of it is gone and test that. You'll have a much higher concentration of any contaminants.